1. Field of the Invention
The present invention relates to safety spectacles, and more particularly to adjustable safety spectacles that include both fore/aft (length) and pantoscopic (lens angle to frame) adjustment mechanisms.
2. Description of Related Art
Because of various safety requirements for employees coupled with a more safety conscious public, the need for safety gear has increased. With this need has come the requirement that the safety equipment must be functional, practical and comfortable. One piece of safety equipment is the spectacle for protecting the eyes.
The prior art discloses many different types of glasses or spectacles with features such as temples having various length and/or pantoscopic adjustment mechanisms. The typical design for adjustable spectacles employs screw means to adjust and maintain the positions of the temples with respect to the frames, as characterized by U.S. Pat. No. 1,252,126 Letzeisen. One shortcoming of utilizing screw means is that it increases the cost of production because of the additional parts and labor required for drilling and assembly.
Numerous attempts have been made to improve the structures and designs of adjustable spectacles in order to make them more comfortable for the user. Most notably, U.S. Pat. No. 5,016,292 Rademacher teaches a safety spectacle with length adjustable temples in which knobs on an earpiece can be inserted into a plurality of different holes of a notched region on a telescoping connection. Even though no screw means are employed in the entire spectacle design, the spectacle also does not provide a pantoscopic adjustment mechanism.
A pantoscopic and length adjustable spectacle which does not employ screw means is taught by U.S. Pat. No. 5,289,592 Paivarinta. This patent discloses an eyeglass holder having a pawl and ratchet adjustment mechanism for adjusting the length of the temples, and an arcuate pawl and ratchet adjustment mechanism member for changing the angle of the arms relative to the frame. The spectacle, however, has a design requiring many different parts, including a hinge and pin connection of the temple piece to the frame. Some of the parts are very intricate and thereby expensive to produce. Furthermore, the spectacle does not provide adequately secure locking mechanisms to maintain the positioning of the temples once adjusted.
With the above considerations in mind, an object of the present invention is to provide a safety spectacle with both a length and pantoscopic adjustable temple arm assembly which can be easily constructed with a minimal number of parts and without drilling or screws required for assembly.
Another object of the present invention is to provide a safety spectacle having easily adjustable length and pantoscopic temples.
A further object of the present invention is to provide an easily disassemblable safety spectacle in order to quickly change lenses.